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Birds prepare their eggs from recently ingested nutrients ('income' breeders) or from body stores ('capital' breeders). As summers are short at Arctic latitudes, Arctic migrants have been presumed to bring nutrients for egg production from their previous habitats, so that they can start breeding immediately upon arrival. But we show here that eggs laid by 10 different wader species from 12 localities in northeast Greenland and Arctic Canada are produced from nutrients originating from tundra habitats, as inferred from carbon stable-isotope ratios in eggs, natal down, and juvenile and adult feathers.